The process of drilling, especially in subterranean formations, often involves lifting numerous sections of drill rod and/or casings into place and then connecting the sections together at the joints. The connected sections form a drill string, which is often tipped with a drill bit. Frequently, the joints on the drill rods or casings include male and female threads that may be connected together. During the drilling process, a drill rig applies an axial force and rotates the drill string, often causing these joints to become very tight.
Generally, if the drill string is removed from the borehole (the hole created during drilling) for any reason (e.g., to replace or repair the drill bit), the entire string of drill rods may need to be removed by tripping it out of the borehole, section by section. As this is done, each of the joints for the rods, which now may be extremely tight, may have to be broken and the male and female ends of adjacent rods may need to be separated. In some instances, multiple drill rod sections, which are typically around 5, 10, or 20 feet, may be connected to form a string that extends for very long distances. Thus, a single drill string may have hundreds of joints that may need to be broken and separated.
In many instances, in order to break the joint, the joint is positioned to place the joint near a foot clamp that is located near the bottom of the rig. The foot clamp then clamps the rod while large mechanisms powered by the rig break the joint. In some instances, however, it may be difficult or impractical to position the joint near the foot clamp portion of the drill rig.
Currently, to break and unscrew a joint that is not positioned within the envelope of the foot clamp, several conventional methods are used. First, if possible, the joint can be broken manually using a rigid pipe wrench to break the joint. Second, breaking of the joint may be aided by the power of the rig, using a rigid pipe wrench that is optionally secured against flying off in the event of a failure. And finally, the joint may be broken using whatever it takes to break the joint, i.e., snipes, come-alongs, chain blocks, etc. Such processes may be slow, time consuming, dangerous, and costly because of the cost of labor and the lost opportunity cost.